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Cho H, Kim Y, Hong S, Choi H. Cerebrospinal fluid flow in normal beagle dogs analyzed using magnetic resonance imaging. J Vet Sci 2021; 22:e2. [PMID: 33522154 PMCID: PMC7850791 DOI: 10.4142/jvs.2021.22.e2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 11/29/2022] Open
Abstract
Background Diseases related to cerebrospinal fluid flow, such as hydrocephalus, syringomyelia, and Chiari malformation, are often found in small dogs. Although studies in human medicine have revealed a correlation with cerebrospinal fluid flow in these diseases by magnetic resonance imaging, there is little information and no standard data for normal dogs. Objectives The purpose of this study was to obtain cerebrospinal fluid flow velocity data from the cerebral aqueduct and subarachnoid space at the foramen magnum in healthy beagle dogs. Methods Six healthy beagle dogs were used in this experimental study. The dogs underwent phase-contrast and time-spatial labeling inversion pulse magnetic resonance imaging. Flow rate variations in the cerebrospinal fluid were observed using sagittal time-spatial labeling inversion pulse images. The pattern and velocity of cerebrospinal fluid flow were assessed using phase-contrast magnetic resonance imaging within the subarachnoid space at the foramen magnum level and the cerebral aqueduct. Results In the ventral aspect of the subarachnoid space and cerebral aqueduct, the cerebrospinal fluid was characterized by a bidirectional flow throughout the cardiac cycle. The mean ± SD peak velocities through the ventral and dorsal aspects of the subarachnoid space and the cerebral aqueduct were 1.39 ± 0.13, 0.32 ± 0.12, and 0.76 ± 0.43 cm/s, respectively. Conclusions Noninvasive visualization of cerebrospinal fluid flow movement with magnetic resonance imaging was feasible, and a reference dataset of cerebrospinal fluid flow peak velocities was obtained through the cervical subarachnoid space and cerebral aqueduct in healthy dogs.
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Affiliation(s)
- Hyunju Cho
- Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Yejin Kim
- Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Saebyel Hong
- Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Hojung Choi
- Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea.
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Capra V, Iacomino M, Accogli A, Pavanello M, Zara F, Cama A, De Marco P. Chiari malformation type I: what information from the genetics? Childs Nerv Syst 2019; 35:1665-1671. [PMID: 31385087 DOI: 10.1007/s00381-019-04322-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/28/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE Chiari malformation type I (CMI), a rare disorder of the craniocerebral junction with an estimated incidence of 1 in 1280, is characterized by the downward herniation of the cerebellar tonsils of at least 5 mm through the foramen magnum, resulting in significant neurologic morbidity. Classical CMI is thought to be caused by an underdeveloped occipital bone, resulting in a posterior cranial fossa which is too small to accommodate the normal-sized cerebellum. In this review, we dissect the lines of evidence supporting a genetic contribution for this disorder. METHODS We present the results of two types of approaches: animal models and human studies encompassing different study designs such as whole genome linkage analysis, case-control association studies, and expression studies. The update of the literature also includes the most recent findings emerged by whole exome sequencing strategy. RESULTS Despite evidence for a genetic component, no major genes have been identified and the genetics of CMI is still very much unknown. One major challenge is the variability of clinical presentation within CMI patient population that reflects an underlying genetic heterogeneity. CONCLUSIONS The identification of the genes that contribute to the etiology of CMI will provide an important step to the understanding of the underlying pathology. The finding of a predisposing gene may lead to the development of simple and accurate diagnostic tests for better prognosis, counseling, and clinical management of patients and their relatives.
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Affiliation(s)
- Valeria Capra
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Michele Iacomino
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy.,UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Andrea Accogli
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Marco Pavanello
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Federico Zara
- UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Armando Cama
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Patrizia De Marco
- UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy.
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Rusbridge C, McFadyen AK, Knower SP. Behavioral and clinical signs of Chiari-like malformation-associated pain and syringomyelia in Cavalier King Charles spaniels. J Vet Intern Med 2019; 33:2138-2150. [PMID: 31290195 PMCID: PMC6766577 DOI: 10.1111/jvim.15552] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 06/19/2019] [Indexed: 02/02/2023] Open
Abstract
Background Diagnosis of Chiari‐like malformation‐associated pain (CM‐P) or clinically relevant syringomyelia (SM) is challenging. We sought to determine common signs. Animals One hundred thirty client‐owned Cavalier King Charles spaniels with neuroaxis magnetic resonance imaging (MRI) and diagnosis of CM‐P/SM. Dogs with comorbidities causing similar signs were excluded with exception of otitis media with effusion (OME). Methods Retrospective study of medical records relating signalment, signs, and MRI findings. Dogs were grouped by SM maximum transverse diameter (1 = no SM; 2 = 0.5‐1.99 mm; 3 = 2‐3.9 mm: 4 = ≥4 mm). Differences between all groups—groups 1 versus 2‐4 and groups 1‐3 versus 4—were investigated. Continuous variables were analyzed using 2‐sample t‐tests and analysis of variance. Associations between categorical variables were analyzed using Fisher's exact or chi‐square tests. Results Common signs were vocalization (65.4%), spinal pain (54.6%), reduced activity (37.7%), reduced stairs/jumping ability (35.4%), touch aversion (30.0%), altered emotional state (28.5%), and sleep disturbance (22%). Head scratching/rubbing (28.5%) was inversely associated with syrinx size (P = .005), less common in group 4 (P = .003), and not associated with OME (P = .977). Phantom scratching, scoliosis, weakness, and postural deficits were only seen in group 4 (SM ≥4 mm; P = .004). Conclusions and Clinical Importance Signs of pain are common in CM/SM but are not SM‐dependent, suggesting (not proving) CM‐P causality. Wide (≥4 mm) SM is associated with signs of myelopathy and, if the dorsal horn is involved, phantom scratching (ipsilateral) and torticollis (shoulder deviated ipsilateral; head tilt contralateral).
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Surrey, United Kingdom.,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Surrey, United Kingdom
| | | | - Susan P Knower
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Surrey, United Kingdom
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Sparks CR, Gorney A, Williams K, Griffith EH, Cerda-Gonzalez S, Lascelles BDX, Olby NJ. Investigation of sensory thresholds in Cavalier King Charles Spaniels with and without Chiari-like malformations and syringomyelia. J Vet Intern Med 2018; 32:2021-2028. [PMID: 30307645 PMCID: PMC6272044 DOI: 10.1111/jvim.15297] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/01/2018] [Accepted: 07/17/2018] [Indexed: 11/29/2022] Open
Abstract
Background Cavalier King Charles Spaniels (CKCS) suffer pain associated with Chiari‐like malformation and syringomyelia (CMSM). People suffer from a similar condition and describe numerous sensory abnormalities. Sensory changes have not been quantified in affected CKCS. Objectives To use quantitative sensory testing (QST) to quantify thermal and mechanical thresholds in CKCS and to compare QST in dogs with and without syringomyelia (SM). Animals Forty‐four CKCS. Methods Prospective study. Dogs underwent neurological examinations and craniocervical magnetic resonance imaging (MRI). Thermal testing was performed over the humerus and thorax (n = 32); mechanical testing was performed on the paw and neck (n = 44). Latencies, thresholds, and response rates were compared with presence and severity of SM on MRI, presence of pain reported by the owner and pain identified on examination. Results Thirty dogs had SM, 30 were painful on examination, 29 were owner‐reported symptomatic. Thermal and mechanical variables were not significantly different based on presence or severity of SM. Dogs with pain on examination had decreased mechanical thresholds on the paw (0.38 kg, SD = 0.18) and neck (2.05 kg, SD = 0.74) compared to thresholds of dogs without pain on examination on the paw (0.60 kg, SD = 0.30) and neck (2.72 kg, SD = 0.57; P = .021). Conclusions and Clinical Importance Mechanical and thermal sensitivity does not appear to be related to the presence of SM, but mechanical sensitivity appears to be related to the presence of pain and clinical signs. Mechanical testing may be useful for assessing sensory abnormalities during clinical trials.
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Affiliation(s)
- Courtney R Sparks
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Angela Gorney
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Kim Williams
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Emily H Griffith
- Department of Statistics, North Carolina State University, Raleigh, North Carolina
| | - Sofia Cerda-Gonzalez
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - B Duncan X Lascelles
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Comparative Pain Research and Education Center, North Carolina State University, Raleigh, North Carolina
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Comparative Pain Research and Education Center, North Carolina State University, Raleigh, North Carolina
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5
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Knowler SP, Galea GL, Rusbridge C. Morphogenesis of Canine Chiari Malformation and Secondary Syringomyelia: Disorders of Cerebrospinal Fluid Circulation. Front Vet Sci 2018; 5:171. [PMID: 30101146 PMCID: PMC6074093 DOI: 10.3389/fvets.2018.00171] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/04/2018] [Indexed: 01/01/2023] Open
Abstract
Chiari-like Malformation (CM) and secondary syringomyelia (SM), as well as their analogous human conditions, is a complex developmental condition associated with pain and accompanying welfare concerns. CM/SM is diagnosed ever more frequently, thanks in part to the increased availability of magnetic resonance imaging in veterinary medicine. Research over the last two decades has focused primarily on its pathophysiology relating to overcrowding of the cranial caudal fossa. More recent characterizations of CM/SM include brachycephaly with osseous reduction and neural parenchymal displacement involving the entire brain and craniocervical junction to include rostral flattening, olfactory bulb rotation, increased height of the cranium, reduced cranial base with spheno-occipital synchondrosis angulation, reduced supraoccipital and interparietal crest and rostral displacement of the axis and atlas with increased odontoid angulation. The most shared manifestation of CM is the development of fluid-filled pockets (syrinx, syringes) in the spinal cord that can be readily quantified. Dogs with symptomatic CM without SM have a reduced basioccipital bone, compensatory increased cranial fossa height with displaced parenchyma whereby the cerebellum is invaginated beneath the occipital lobes but without compromising cerebrospinal fluid channels enough to cause SM. Thus, broadly defined, CM might be described as any distortion of the skull and craniocervical junction which compromises the neural parenchyma and cerebrospinal fluid circulation causing pain and/or SM. The etiology of CM is multifactorial, potentially including genetically-influenced, breed-specific abnormalities in both skeletal and neural components. Since causation between specific morphologic changes and SM or clinical signs is unproven, CM might be more appropriately considered as a brachycephalic obstructive CSF channel syndrome (BOCCS) rather than a single malformation. Understanding the normal development of the brain, skull and craniocervical junction is fundamental to identifying deviations which predispose to CM/SM. Here we review its anatomical, embryological, bio-mechanical, and genetic underpinnings to update the profession's understanding of this condition and meaningfully inform future research to diminish its welfare impact.
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Affiliation(s)
- Susan P Knowler
- Department of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Gabriel L Galea
- Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College London, London,, United Kingdom
| | - Clare Rusbridge
- Department of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Fitzpatrick Referrals Veterinary Specialist Hospital, Surrey, United Kingdom
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Abstract
Background Syringomyelia is a pathological condition in which fluid-filled cavities (syringes) form and expand in the spinal cord. Syringomyelia is often linked with obstruction of the craniocervical junction and a Chiari malformation, which is similar in both humans and animals. Some brachycephalic toy breed dogs such as Cavalier King Charles Spaniels (CKCS) are particularly predisposed. The exact mechanism of the formation of syringomyelia is undetermined and consequently with the lack of clinical explanation, engineers and mathematicians have resorted to computer models to identify possible physical mechanisms that can lead to syringes. We developed a computer model of the spinal cavity of a CKCS suffering from a large syrinx. The model was excited at the cranial end to simulate the movement of the cerebrospinal fluid (CSF) and the spinal cord due to the shift of blood volume in the cranium related to the cardiac cycle. To simulate the normal condition, the movement was prescribed to the CSF. To simulate the pathological condition, the movement of CSF was blocked. Results For normal conditions the pressure in the SAS was approximately 400 Pa and the same applied to all stress components in the spinal cord. The stress was uniformly distributed along the length of the spinal cord. When the blockage between the cranial and spinal CSF spaces forced the cord to move with the cardiac cycle, shear and axial normal stresses in the cord increased significantly. The sites where the elevated stress was most pronounced coincided with the axial locations where the syringes typically form, but they were at the perimeter rather than in the central portion of the cord. This elevated stress originated from the bending of the cord at the locations where its curvature was high. Conclusions The results suggest that it is possible that repetitive stressing of the spinal cord caused by its exaggerated movement could be a cause for the formation of initial syringes. Further consideration of factors such as cord tethering and the difference in mechanical properties of white and grey matter is needed to fully explore this possibility. Electronic supplementary material The online version of this article (10.1186/s12917-018-1410-7) contains supplementary material, which is available to authorized users.
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7
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Sparks CR, Cerda-Gonzalez S, Griffith EH, Lascelles BDX, Olby NJ. Questionnaire-based Analysis of Owner-reported Scratching and Pain Signs in Cavalier King Charles Spaniels Screened for Chiari-like Malformation and Syringomyelia. J Vet Intern Med 2017; 32:331-339. [PMID: 29105875 PMCID: PMC5787193 DOI: 10.1111/jvim.14856] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/25/2017] [Accepted: 09/19/2017] [Indexed: 12/14/2022] Open
Abstract
Background Chiari‐like malformation (CM) and syringomyelia (SM) cause a pain syndrome in Cavalier King Charles spaniels (CKCS). Clinical signs are not consistently apparent on neurologic examination, and owner reporting of signs provides vital clinical history. However, owner questionnaires for this disease are not well developed. Objectives To develop a tool to capture owner‐reported clinical signs for use in clinical trials and to compare owner‐reported signs with the presence of pain on neurologic examination and SM on magnetic resonance imaging (MRI). Animals Fifty client‐owned CKCS. Methods Owners completed a questionnaire and pain/scratch map. Each dog underwent a neurologic examination and craniocervical magnetic resonance imaging (MRI). Questionnaire responses were developed into scores, area of shading for pain/scratch maps was measured, and consistency of responses between these tools was assessed. Owner‐reported findings were compared with neurologic examination findings and presence and severity of SM on MRI. Results Thirty‐three dogs were symptomatic and 17 asymptomatic; 30 had SM. The most common sign of pain was crying out when lifted (n = 11). Extent of shaded areas on maps positively correlated with questionnaire scores for pain (r2 = 0.213, P = 0.006) and scratch (r2 = 0.104, P = 0.089). Owner‐reported findings were not significantly associated with presence or severity of SM or neurologic examination findings. Owner‐reported lateralization of signs was significantly associated with SM lateralization (P < 0.0001). Conclusions The questionnaire and maps may be useful for clinical trials. Lack of association of owner‐reported signs with SM highlights our lack of understanding of the pathophysiology of pain in this disease.
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Affiliation(s)
- C R Sparks
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - S Cerda-Gonzalez
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - E H Griffith
- Department of Statistics, North Carolina State University, Raleigh, NC
| | - B D X Lascelles
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC.,Comparative Pain Research and Education Center, North Carolina State University, Raleigh, NC
| | - N J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC
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Knowler SP, v/d Berg H, McFadyen A, La Ragione RM, Rusbridge C. Inheritance of Chiari-Like Malformation: Can a Mixed Breeding Reduce the Risk of Syringomyelia? PLoS One 2016; 11:e0151280. [PMID: 27008271 PMCID: PMC4805231 DOI: 10.1371/journal.pone.0151280] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/25/2016] [Indexed: 12/05/2022] Open
Abstract
Canine Chiari-like malformation (CM) is a complex abnormality of the skull and craniocervical junction associated with miniaturization and brachycephaly which can result in the spinal cord disease syringomyelia (SM). This study investigated the inheritance of CM in a Griffon Bruxellois (GB) family and feasibility of crossbreeding a brachycephalic CM affected GB with a mesaticephalic normal Australian terrier and then backcrossing to produce individuals free of the malformation and regain GB breed characteristics. The study family cohort (n = 27) included five founder dogs from a previous baseline study of 155 GB which defined CM as a global malformation of the cranium and craniocervical junction with a shortened skull base and increased proximity of the cervical vertebrae to the skull. T1-weighted sagittal DICOM images of the brain and craniocervical junction were analysed for five significant traits (two angles, three lines) identified from the previous study and subsequent Qualitative Trait Loci analysis. Mean measurements for mixed breed, pure-breed and baseline study groups were compared. Results indicated that mixed breed traits posed less risk for CM and SM and were useful to distinguish the phenotype. Moreover on the MR images, the filial relationships displayed by the traits exhibited segregation and those presenting the greatest risk for CM appeared additive towards the severity of the condition. The external phenotypes revealed that by outcrossing breed types and with careful selection of appropriate conformation characteristics in the first generation, it is possible to regain the GB breed standard and reduce the degree of CM. The four GB affected with SM in the study all exhibited reduced caudal skull development compared to their relatives. The craniocervical traits may be useful for quantifying CM and assessing the possibility of SM thus assisting breeders with mate selection. However, such a system requires validation to ensure appropriateness for all breeds at risk.
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Affiliation(s)
- Susan P. Knowler
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Henny v/d Berg
- Fitzpatrick Referrals, Eashing, Godalming, Surrey, United Kingdom
| | | | - Roberto M. La Ragione
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Clare Rusbridge
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
- Fitzpatrick Referrals, Eashing, Godalming, Surrey, United Kingdom
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International Veterinary Epilepsy Task Force's current understanding of idiopathic epilepsy of genetic or suspected genetic origin in purebred dogs. BMC Vet Res 2015; 11:175. [PMID: 26316206 PMCID: PMC4552344 DOI: 10.1186/s12917-015-0463-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/29/2015] [Indexed: 12/20/2022] Open
Abstract
Canine idiopathic epilepsy is a common neurological disease affecting both purebred and crossbred dogs. Various breed-specific cohort, epidemiological and genetic studies have been conducted to date, which all improved our knowledge and general understanding of canine idiopathic epilepsy, and in particular our knowledge of those breeds studied. However, these studies also frequently revealed differences between the investigated breeds with respect to clinical features, inheritance and prevalence rates. Awareness and observation of breed-specific differences is important for successful management of the dog with epilepsy in everyday clinical practice and furthermore may promote canine epilepsy research. The following manuscript reviews the evidence available for breeds which have been identified as being predisposed to idiopathic epilepsy with a proven or suspected genetic background, and highlights different breed specific clinical features (e.g. age at onset, sex, seizure type), treatment response, prevalence rates and proposed inheritance reported in the literature. In addition, certain breed-specific diseases that may act as potential differentials for idiopathic epilepsy are highlighted.
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10
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Abstract
This article summarizes the current understanding of the pathophysiology of the Chiari I malformation that is based on observations of the anatomy visualized by modern imaging with MRI and prospective studies of the physiology of patients before and after surgery. The pathogenesis of a Chiari I malformation of the cerebellar tonsils is grouped into 4 general mechanisms.
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Schmidt MJ, Laubner S, Kolecka M, Failing K, Moritz A, Kramer M, Ondreka N. Comparison of the Relationship between Cerebral White Matter and Grey Matter in Normal Dogs and Dogs with Lateral Ventricular Enlargement. PLoS One 2015; 10:e0124174. [PMID: 25938575 PMCID: PMC4418575 DOI: 10.1371/journal.pone.0124174] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 03/13/2015] [Indexed: 11/18/2022] Open
Abstract
Large cerebral ventricles are a frequent finding in brains of dogs with brachycephalic skull conformation, in comparison with mesaticephalic dogs. It remains unclear whether oversized ventricles represent a normal variant or a pathological condition in brachycephalic dogs. There is a distinct relationship between white matter and grey matter in the cerebrum of all eutherian mammals. The aim of this study was to determine if this physiological proportion between white matter and grey matter of the forebrain still exists in brachycephalic dogs with oversized ventricles. The relative cerebral grey matter, white matter and cerebrospinal fluid volume in dogs were determined based on magnetic-resonance-imaging datasets using graphical software. In an analysis of covariance (ANCOVA) using body mass as the covariate, the adjusted means of the brain tissue volumes of two groups of dogs were compared. Group 1 included 37 mesaticephalic dogs of different sizes with no apparent changes in brain morphology, and subjectively normal ventricle size. Group 2 included 35 brachycephalic dogs in which subjectively enlarged cerebral ventricles were noted as an incidental finding in their magnetic-resonance-imaging examination. Whereas no significant different adjusted means of the grey matter could be determined, the group of brachycephalic dogs had significantly larger adjusted means of lateral cerebral ventricles and significantly less adjusted means of relative white matter volume. This indicates that brachycephalic dogs with subjective ventriculomegaly have less white matter, as expected based on their body weight and cerebral volume. Our study suggests that ventriculomegaly in brachycephalic dogs is not a normal variant of ventricular volume. Based on the changes in the relative proportion of WM and CSF volume, and the unchanged GM proportions in dogs with ventriculomegaly, we rather suggest that distension of the lateral ventricles might be the underlying cause of pressure related periventricular loss of white matter tissue, as occurs in internal hydrocephalus.
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Affiliation(s)
- Martin J. Schmidt
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
- * E-mail:
| | - Steffi Laubner
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
| | - Malgorzata Kolecka
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
| | - Klaus Failing
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig-University-Giessen, Giessen, Germany
| | - Andreas Moritz
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
| | - Martin Kramer
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
| | - Nele Ondreka
- Department of Veterinary Clinical Sciences, Clinic for Small Animals, Justus-Liebig-University-Giessen, Giessen, Germany
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12
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Prevalence of disorders recorded in Cavalier King Charles Spaniels attending primary-care veterinary practices in England. Canine Genet Epidemiol 2015; 2:4. [PMID: 26401332 PMCID: PMC4579365 DOI: 10.1186/s40575-015-0016-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 03/17/2015] [Indexed: 11/10/2022] Open
Abstract
Background Concerns have been raised over breed-related health issues in purebred dogs, but reliable prevalence estimates for disorders within specific breeds are sparse. Electronically stored patient health records from primary-care practice are emerging as a useful source of epidemiological data in companion animals. This study used large volumes of health data from UK primary-care practices participating in the VetCompass animal health surveillance project to evaluate in detail the disorders diagnosed in a random selection of over 50% of dogs recorded as Cavalier King Charles Spaniels (CKCSs). Confirmation of breed using available microchip and Kennel Club (KC) registration data was attempted. Results In total, 3624 dogs were recorded as CKCSs within the VetCompass database of which 143 (3.9%) were confirmed as KC-registered via microchip identification linkage of VetCompass to the KC database. 1875 dogs (75 KC registered and 1800 of unknown KC status, 52% of both groups) were randomly sampled for detailed clinical review. Clinical data associated with veterinary care were recorded in 1749 (93.3%) of these dogs. The most common specific disorders recorded during the study period were heart murmur (541 dogs, representing 30.9% of study group), diarrhoea of unspecified cause (193 dogs, 11.0%), dental disease (166 dogs, 9.5%), otitis externa (161, 9.2%), conjunctivitis (131, 7.4%) and anal sac infection (129, 7.4%). The five most common disorder categories were cardiac (affecting 31.7% of dogs), dermatological (22.2%), ocular (20.6%), gastrointestinal (19.3%) and dental/periodontal disorders (15.2%). Discussion and conclusions Study findings suggest that many of the disorders commonly affecting CKCSs are largely similar to those affecting the general dog population presented for primary veterinary care in the UK. However, cardiac disease (and MVD in particular) continues to be of particular concern in this breed. Further work This work highlights the value of veterinary practice based breed-specific epidemiological studies to provide targeted and evidence-based health policies. Further studies using electronic patient records in other breeds could highlight their potential disease predispositions.
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Mitchell TJ, Knowler SP, van den Berg H, Sykes J, Rusbridge C. Syringomyelia: determining risk and protective factors in the conformation of the Cavalier King Charles Spaniel dog. Canine Genet Epidemiol 2014; 1:9. [PMID: 26401326 PMCID: PMC4579371 DOI: 10.1186/2052-6687-1-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 07/18/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Syringomyelia (SM) is a painful neurological condition, prevalent in brachycephalic toy breeds including the Cavalier King Charles Spaniel (CKCS). In these breeds, SM is typically secondary to Chiari-like Malformation (CM). There has been much debate in the scientific and veterinary communities to what extent head shape is indicative of either pathology, especially as certain craniosynostosis syndromes in humans (highly associated with CM) have characteristic facial and cranial morphologies. Elucidating a risk morphology would allow for selection away from these traits and proffer further breeding guidelines for the condition. Dogs were measured in multiple countries by means of a standardised bony landmark measuring protocol and photo analysis by blinded, trained researchers. RESULTS The results found two significant risk factors in the conformation of the CKCS: extent of brachycephaly and distribution of cranium. The study identified a greater amount of cranium distributed caudally (relative to the amount distributed rostrally) to be significantly protective against syrinx development at the levels of three years of age, five years of age and when comparing a sample of SM clear individuals over the age of five to those affected younger than three years of age. A decreased cephalic index (decreasing brachycephaly) was significantly protective at the latter level. Cephalic index and caudal cranium distribution exhibited a negative, linear relationship. Cephalic index demonstrated a positive linear relationship with the amount of doming of the head. CONCLUSIONS This study proposes a risk phenotype of brachycephaly with resulting rostrocaudal doming that is more rostrally distributed and hence sloping caudally. The results of this study may allow for selection against risk aspects of conformation in the CKCS in combination with the British Veterinary Association/Kennel Club CM/SM scheme to enable reduction in CM/SM incidence. Further research comparing this external risk phenotype to the internal presentation upon MRI would determine how these features are indicative of syrinx development. Utilising breeds in which CM free individuals are more available may allow for validation of this risk phenotype for CM or determine alternatives.
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Affiliation(s)
- Thomas J Mitchell
- School of Clinical Veterinary Science, University of Bristol, Langford, Bristol BS40 5DU UK
| | - Susan P Knowler
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Duke of Kent Building, Guildford, Surrey GU2 7TE UK
| | - Henny van den Berg
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, Surrey GU7 2QQ UK
| | - Jane Sykes
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2 Canada
| | - Clare Rusbridge
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Duke of Kent Building, Guildford, Surrey GU2 7TE UK ; Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, Surrey GU7 2QQ UK
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Lemay P, Knowler SP, Bouasker S, Nédélec Y, Platt S, Freeman C, Child G, Barreiro LB, Rouleau GA, Rusbridge C, Kibar Z. Quantitative trait loci (QTL) study identifies novel genomic regions associated to Chiari-like malformation in Griffon Bruxellois dogs. PLoS One 2014; 9:e89816. [PMID: 24740420 PMCID: PMC3989173 DOI: 10.1371/journal.pone.0089816] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 01/25/2014] [Indexed: 11/18/2022] Open
Abstract
Chiari-like malformation (CM) is a developmental abnormality of the craniocervical junction that is common in the Griffon Bruxellois (GB) breed with an estimated prevalence of 65%. This disease is characterized by overcrowding of the neural parenchyma at the craniocervical junction and disturbance of cerebrospinal fluid (CSF) flow. The most common clinical sign is pain either as a direct consequence of CM or neuropathic pain as a consequence of secondary syringomyelia. The etiology of CM remains unknown but genetic factors play an important role. To investigate the genetic complexity of the disease, a quantitative trait locus (QTL) approach was adopted. A total of 14 quantitative skull and atlas measurements were taken and were tested for association to CM. Six traits were found to be associated to CM and were subjected to a whole-genome association study using the Illumina canine high density bead chip in 74 GB dogs (50 affected and 24 controls). Linear and mixed regression analyses identified associated single nucleotide polymorphisms (SNPs) on 5 Canis Familiaris Autosomes (CFAs): CFA2, CFA9, CFA12, CFA14 and CFA24. A reconstructed haplotype of 0.53 Mb on CFA2 strongly associated to the height of the cranial fossa (diameter F) and an haplotype of 2.5 Mb on CFA14 associated to both the height of the rostral part of the caudal cranial fossa (AE) and the height of the brain (FG) were significantly associated to CM after 10 000 permutations strengthening their candidacy for this disease (P = 0.0421, P = 0.0094 respectively). The CFA2 QTL harbours the Sall-1 gene which is an excellent candidate since its orthologue in humans is mutated in Townes-Brocks syndrome which has previously been associated to Chiari malformation I. Our study demonstrates the implication of multiple traits in the etiology of CM and has successfully identified two new QTL associated to CM and a potential candidate gene.
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Affiliation(s)
- Philippe Lemay
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, Quebec, Canada
| | | | - Samir Bouasker
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, Quebec, Canada
| | - Yohann Nédélec
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, Quebec, Canada
| | - Simon Platt
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Courtenay Freeman
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Georgina Child
- Small Animal Specialist Hospital, Sydney, New South Wales, Australia
| | - Luis B. Barreiro
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, Quebec, Canada
| | - Guy A. Rouleau
- Montreal Neurological Institute and McGill University, Montreal, Canada
| | - Clare Rusbridge
- Fitzpatrick Referrals, Goldaming, Surrey, United Kingdom
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Zoha Kibar
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, Quebec, Canada
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Knowler SP, McFadyen AK, Freeman C, Kent M, Platt SR, Kibar Z, Rusbridge C. Quantitative analysis of Chiari-like malformation and syringomyelia in the Griffon Bruxellois dog. PLoS One 2014; 9:e88120. [PMID: 24533070 PMCID: PMC3922758 DOI: 10.1371/journal.pone.0088120] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 01/04/2014] [Indexed: 11/28/2022] Open
Abstract
This study aimed to develop a system of quantitative analysis of canine Chiari-like malformation and syringomyelia on variable quality MRI. We made a series of measurements from magnetic resonance DICOM images from Griffon Bruxellois dogs with and without Chiari-like malformation and syringomyelia and identified several significant variables. We found that in the Griffon Bruxellois dog, Chiari-like malformation is characterized by an apparent shortening of the entire cranial base and possibly by increased proximity of the atlas to the occiput. As a compensatory change, there appears to be an increased height of the rostral cranial cavity with lengthening of the dorsal cranial vault and considerable reorganization of the brain parenchyma including ventral deviation of the olfactory bulbs and rostral invagination of the cerebellum under the occipital lobes.
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Affiliation(s)
- Susan P. Knowler
- Neurology Department, Fitzpatrick Referrals, Godalming, Surrey, United Kingdom
| | | | - Courtenay Freeman
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Marc Kent
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Simon R. Platt
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Zoha Kibar
- Department of Neurosciences, Justine University Hospital Research Center, University of Montreal, Quebec, Canada
| | - Clare Rusbridge
- Neurology Department, Fitzpatrick Referrals, Godalming, Surrey, United Kingdom
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
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16
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Welsch M, Antes S, Kiefer M, Meyer S, Eymann R. Association of Chiari malformation and vitamin B12 deficit in a family. Childs Nerv Syst 2013; 29:1193-8. [PMID: 23468202 DOI: 10.1007/s00381-013-2056-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 02/15/2013] [Indexed: 10/27/2022]
Abstract
PURPOSE A clear etiology of Chiari malformation is still lacking. Some associations between this disorder and genetical variations have been reported. Documented cases of familial Chiari malformation in three consecutive generations are rare. Furthermore, an association of Chiari disorder and vitamin B12 deficit has rarely been described in literature. METHODS In this study, three generations of a family suffering from Chiari 1 or Chiari 0 malformation have been examined with MRI, clinically and laboratory (hemograms). RESULTS Chiari malformation could be confirmed in all presented patients: While the F2 generation (children: 1 × ♀, 1 × ♂) and the female F1 generation (mother and sister of mother) suffered from Chiari type 1, the male F0 generation showed Chiari 0 malformation. F0 and F1 generation further presented with syringomyelia (F0: C4-D1; F1: C4-D2). All patients except the grandfather (F0) underwent surgical posterior fossa decompression to relive successfully cerebellar and hydrocephalus associated progressing clinical symptoms. The hemograms of generation 1 and 2 revealed familial vitamin B12 deficit. CONCLUSIONS A hereditary component is discussed in Chiari malformation, yet proved etiology is still lacking. As folic acid plays an important role in the development of the neural tube, vitamin B12 deficit might have some impact on the development of Chiari malformations.
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Affiliation(s)
- Melanie Welsch
- Department of Neurosurgery, Mannheim University Hospital, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Sebastian Antes
- Department of Neurosurgery, Medical School, Saarland University, Kirrberger Straße, Building 90.5, 66421, Homburg-Saar, Germany
| | - Michael Kiefer
- Department of Neurosurgery, Medical School, Saarland University, Kirrberger Straße, Building 90.5, 66421, Homburg-Saar, Germany
| | - Sascha Meyer
- Department of Pediatrics and Neonatology; Section Neuropediatrics, Saarland University, Homburg, Germany
| | - Regina Eymann
- Department of Neurosurgery, Medical School, Saarland University, Kirrberger Straße, Building 90.5, 66421, Homburg-Saar, Germany
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Driver CJ, De Risio L, Hamilton S, Rusbridge C, Dennis R, McGonnell IM, Volk HA. Changes over time in craniocerebral morphology and syringomyelia in cavalier King Charles spaniels with Chiari-like malformation. BMC Vet Res 2012; 8:215. [PMID: 23136935 PMCID: PMC3514376 DOI: 10.1186/1746-6148-8-215] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 10/31/2012] [Indexed: 01/22/2023] Open
Abstract
Background Chiari-like malformation (CM) and syringomyelia is a neurological disease complex with high prevalence in cavalier King Charles spaniels (CKCS). The natural progression of this disease with time has not been described. The objectives of this study were to i) determine if syringomyelia progresses with time ii) determine if features of craniocrebral morphology previously associated with CM are progressive (including caudal cranial fossa volume, caudal cranial fossa parenchymal volume, ventricular dimensions, height of the foramen magnum and degree of cerebellar herniation). A retrospective morphometric analysis was undertaken in 12 CKCS with CM for which repeat magnetic resonance images were available without surgical intervention. Results The maximal syrinx width, height of the foramen magnum, length of cerebellar herniation and caudal cranial fossa volume increased over time. Ventricular and caudal fossa parenchymal volumes were not significantly different between scans. Conclusions The results of this study suggest that syringomyelia progresses with time. Increased caudal cranial fossa volume may be associated with active resorption of the supraoccipital bone, which has previously been found in histology specimens from adult CKCS. We hypothesise that active resorption of the supraoccipital bone occurs due to pressure from the cerebellum. These findings have important implications for our understanding of the pathogenesis and variable natural clinical progression of CM and syringomyelia in CKCS.
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Affiliation(s)
- Colin J Driver
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, UK.
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18
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Shaw TA, McGonnell IM, Driver CJ, Rusbridge C, Volk HA. Increase in cerebellar volume in Cavalier King Charles Spaniels with Chiari-like malformation and its role in the development of syringomyelia. PLoS One 2012; 7:e33660. [PMID: 22506005 PMCID: PMC3323625 DOI: 10.1371/journal.pone.0033660] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 02/19/2012] [Indexed: 12/14/2022] Open
Abstract
Previous research in Cavalier King Charles Spaniels (CKCS) has found that Chiari-like malformation and syringomyelia (CM/SM) are associated with a volume mismatch between the caudal cranial fossa (CCF) and the brain parenchyma contained within. The objectives of this study were to i) compare cerebellar volume in CKCS (a "high risk' group which frequently develops CM/SM), small breed dogs (medium risk--occasionally develop CM/SM), and Labradors (low risk--CM/SM not reported); ii) evaluate a possible association between increased cerebellar volume and CM/SM in CKCS; iii) investigate the relationship between increased cerebellar volume and crowding of the cerebellum in the caudal part of the CCF (i.e. the region of the foramen magnum). Volumes of three-dimensional, magnetic resonance imaging derived models of the CCF and cerebellum were obtained from 75 CKCS, 44 small breed dogs, and 31 Labradors. As SM is thought to be a late onset disease process, two subgroups were formed for comparison: 18 CKCS younger than 2 years with SM (CM/SM group) and 13 CKCS older than 5 years without SM (CM group). Relative cerebellar volume was defined as the volume of the cerebellum divided by the total volume of brain parenchyma. Our results show that the CKCS has a relatively larger cerebellum than small breed dogs and Labradors and provide evidence that increased cerebellar volume in CKCS is associated with crowding of cerebellum in the caudal part of the CCF. In CKCS there is an association between increased cerebellar volume and SM. These findings have implications for the understanding of the pathological mechanisms of CM/SM, and support the hypothesis that it is a multifactorial disease process governed by increased cerebellar volume and failure of the CCF to reach a commensurate size.
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Affiliation(s)
- Thomas A. Shaw
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Imelda M. McGonnell
- Department of Veterinary Basic Sciences, The Royal Veterinary College, London, United Kingdom
| | - Colin J. Driver
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Clare Rusbridge
- Stone Lion Veterinary Hospital, Wimbledon, London, United Kingdom
| | - Holger A. Volk
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
- * E-mail:
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Walmsley GL, Arechavala-Gomeza V, Fernandez-Fuente M, Burke MM, Nagel N, Holder A, Stanley R, Chandler K, Marks SL, Muntoni F, Shelton GD, Piercy RJ. A duchenne muscular dystrophy gene hot spot mutation in dystrophin-deficient cavalier king charles spaniels is amenable to exon 51 skipping. PLoS One 2010; 5:e8647. [PMID: 20072625 PMCID: PMC2800183 DOI: 10.1371/journal.pone.0008647] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 12/10/2009] [Indexed: 11/26/2022] Open
Abstract
Background Duchenne muscular dystrophy (DMD), which afflicts 1 in 3500 boys, is one of the most common genetic disorders of children. This fatal degenerative condition is caused by an absence or deficiency of dystrophin in striated muscle. Most affected patients have inherited or spontaneous deletions in the dystrophin gene that disrupt the reading frame resulting in unstable truncated products. For these patients, restoration of the reading frame via antisense oligonucleotide-mediated exon skipping is a promising therapeutic approach. The major DMD deletion “hot spot” is found between exons 45 and 53, and skipping exon 51 in particular is predicted to ameliorate the dystrophic phenotype in the greatest number of patients. Currently the mdx mouse is the most widely used animal model of DMD, although its mild phenotype limits its suitability in clinical trials. The Golden Retriever muscular dystrophy (GRMD) model has a severe phenotype, but due to its large size, is expensive to use. Both these models have mutations in regions of the dystrophin gene distant from the commonly mutated DMD “hot spot”. Methodology/Principal Findings Here we describe the severe phenotype, histopathological findings, and molecular analysis of Cavalier King Charles Spaniels with dystrophin-deficient muscular dystrophy (CKCS-MD). The dogs harbour a missense mutation in the 5′ donor splice site of exon 50 that results in deletion of exon 50 in mRNA transcripts and a predicted premature truncation of the translated protein. Antisense oligonucleotide-mediated skipping of exon 51 in cultured myoblasts from an affected dog restored the reading frame and protein expression. Conclusions/Significance Given the small size of the breed, the amiable temperament and the nature of the mutation, we propose that CKCS-MD is a valuable new model for clinical trials of antisense oligonucleotide-induced exon skipping and other therapeutic approaches for DMD.
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Affiliation(s)
- Gemma L. Walmsley
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | | | - Marta Fernandez-Fuente
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
| | - Margaret M. Burke
- Pathology Laboratory, Harefield Hospital, Royal Brompton & Harefield NHS Foundation Trust, Harefield, Middlesex, United Kingdom
| | - Nicole Nagel
- Alphapet Veterinary Clinic, Bognor Regis, West Sussex, United Kingdom
| | - Angela Holder
- Pathology and Infectious Diseases, Royal Veterinary College, London, United Kingdom
| | - Rachael Stanley
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | - Kate Chandler
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | - Stanley L. Marks
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
| | - G. Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Richard J. Piercy
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
- * E-mail:
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Dewey CW, Marino DJ, Bailey KS, Loughin CA, Barone G, Bolognese P, Milhorat TH, Poppe DJ. Foramen Magnum Decompression with Cranioplasty for Treatment of Caudal Occipital Malformation Syndrome in Dogs. Vet Surg 2007; 36:406-15. [PMID: 17614921 DOI: 10.1111/j.1532-950x.2007.00286.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To describe a cranioplasty procedure used in conjunction with foramen magnum decompression (FMD) for the treatment of canine caudal occipital malformation syndrome (COMS), and to evaluate the clinical outcome. STUDY DESIGN Prospective clinical study. ANIMALS Dogs (n=21) with COMS diagnosed by magnetic resonance imaging (MRI). METHODS After FMD, titanium screws were placed around the perimeter of the foramen magnum defect and a skull plate fashioned from titanium mesh and polymethylmethacrylate was attached to the back of the skull, using the titanium screws as anchor posts. Follow-up was obtained by direct examination by the authors, telephone interviews with owners and referring veterinarians, and a questionnaire sent to owners of surviving dogs designed to assign objective measures of response to surgical intervention. Surgical success was defined as improvement in >or=1 aspects of clinical dysfunction (e.g. scratching, pain) postoperatively. Owner-assigned pre- and postoperative quality-of-life (QOL) scores (1-5) for surviving dogs were compared using a Wilcoxon's signed rank test for paired data (P<or=.05). RESULTS No intraoperative complications occurred and postoperative complications were limited to transient worsening of a pre-existing head tilt and ataxia in 1 dog, and the need for oral pain medication for 1-4 weeks in 3 dogs. Seventeen dogs (81%) had clinical improvement after surgery. Although clinical signs resolved in 1 dog, it died after being hit by a car, 5 months after surgery. One dog had no change in clinical signs; this patient's clinical signs were not severe and the owners had opted for surgery primarily to prevent progression of disease. Two dogs were euthanatized; 1 because of no improvement of severe clinical signs, and 1 because of sustained recurrence of apparent head and neck pain 7 months later. One dog required a dorsal laminectomy at a second site (C1/C2 vertebral level), 2 months later. Four dogs has transient "flare-ups" of apparent head/neck pain 2-13 months later; all resolved with transient re-institution of oral analgesic therapy. Further surgery at the FMD was not needed. Based on the returned questionnaires, there was an overall significant improvement in QOL scores. CONCLUSIONS FMD with cranioplasty was well tolerated, with no intraoperative complications, and minor postoperative complications. Most dogs improved clinically, and none required further surgery at the original FMD site. CLINICAL RELEVANCE FMD with cranioplasty may be an effective surgical method of treating dogs with COMS and is well tolerated. Based on prior reports of FMD for this disorder, it appears that cranioplasty may reduce the rate of surgical failure caused by formation of compressive scar tissue at the FMD site in the short term. Results of this preliminary study support further evaluation of the cranioplasty procedure in a larger group of dogs over a more extended follow-up period.
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Affiliation(s)
- Curtis W Dewey
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
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Rusbridge C. Chiari-Like Malformation with Syringomyelia in the Cavalier King Charles Spaniel: Long-Term Outcome After Surgical Management. Vet Surg 2007; 36:396-405. [PMID: 17614920 DOI: 10.1111/j.1532-950x.2007.00285.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate long-term success of cranial cervical decompression for management of canine Chiari-like malformation with syringomyelia (CM/SM). STUDY DESIGN Retrospective clinical study. ANIMALS Cavalier King Charles spaniels (n=15). METHODS After diagnosis by magnetic resonance imaging (MRI) dogs had cranial cervical decompression with durotomy. Seven dogs had the durotomy patched with biocompatible collagen matrix. Clinical outcome was monitored for >12 months. RESULTS All dogs either improved (80%) or were unchanged (20%) postoperatively. Postoperative MRI in 6 dogs revealed persistence of syringomyelia. Seven dogs (47%) subsequently deteriorated, 0.2-2.3 years after surgery (mean, 1.3 years) and 2 dogs were eventually euthanatized as a consequence. Twelve dogs were still alive, 1-6.5 years after surgery (mean, 2.5 years). CONCLUSION Cranial cervical decompression surgery is associated with low mortality and morbidity, and results in clinical improvement in most dogs. The procedure seemingly does not result in syrinx collapse and resolution. Clinical improvement may not be sustained and some dogs can be expected to deteriorate. CLINICAL RELEVANCE Cranial cervical decompression surgery may have a role in management of CM/SM. In dogs with severe pain, it can improve quality of life for several years; however, it does not appear to adequately address the primary cause of syringomyelia. Further prospective study is needed to better understand the pathogenesis and treatment of this disorder. Because this condition causes neuropathic pain but does not necessarily result in euthanasia more information is needed on appropriate pain management for these patients.
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Rusbridge C, Carruthers H, Dubé MP, Holmes M, Jeffery ND. Syringomyelia in cavalier King Charles spaniels: the relationship between syrinx dimensions and pain. J Small Anim Pract 2007; 48:432-6. [PMID: 17608656 DOI: 10.1111/j.1748-5827.2007.00344.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES This study was designed to test the hypothesis that pain associated with syringomyelia in dogs is dependent upon size and involvement of the dorsal part of the spinal cord. METHODS Masked observers determined syrinx dimensions and precise location within the spinal cord on magnetic resonance images of 55 cavalier King Charles spaniels with syringomyelia. After removal of masking, syrinx size and location were compared between the cohorts of dogs that exhibited pain with those that did not. RESULTS Maximum syrinx width was the strongest predictor of pain, scratching behaviour and scoliosis in dogs with syringomyelia. Both pain and syrinx size were positively correlated with syrinxes located in the dorsal half of the spinal cord. CLINICAL SIGNIFICANCE Large syrinxes associated with damage to the dorsal part of the spinal cord are associated with persistent pain suggesting that the pain behaviour expressed by this group of patients is likely to be "neuropathic pain," resulting from disordered neural processing in the damaged dorsal horn. As such it is likely that conventional analgesic medication may be ineffective.
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Affiliation(s)
- C Rusbridge
- Stone Lion Veterinary Centre, 41 High Street, Wimbledon Village, London SW19 5AU, UK
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Rusbridge C, Knowler SP. Coexistence of occipital dysplasia and occipital hypoplasia/syringomyelia in the cavalier King Charles spaniel. J Small Anim Pract 2006; 47:603-6. [PMID: 17004953 DOI: 10.1111/j.1748-5827.2006.00048.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Concurrent occurrence of occipital dysplasia and occipital hypoplasia in two dogs is described in this report. Occipital hypoplasia results in reduced volume of the caudal fossa, leading to overcrowding of the neural structures and, in severe cases, development of syringomyelia. In occipital dysplasia, there is a failure of complete ossification of the supraoccipital bone. When the two conditions occur concurrently, it is possible that syringomyelia may develop more slowly, resulting in presentation with clinical signs in middle to old age. This has implications for screening tests for early detection of syringomyelia, with a view to using the dog for breeding purposes, as dogs with an apparently mild phenotype for occipital hypoplasia/syringomyelia may actually have a more severe genotype.
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Affiliation(s)
- C Rusbridge
- Stone Lion Veterinary Centre, Goddard Veterinary Group, 41 High Street, Wimbledon, London SW19 5AU
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Dewey CW, Berg JM, Barone G, Marino DJ, Stefanacci JD. Foramen magnum decompression for treatment of caudal occipital malformation syndrome in dogs. J Am Vet Med Assoc 2005; 227:1270-5, 1250-1. [PMID: 16266016 DOI: 10.2460/javma.2005.227.1270] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A method for foramen magnum decompression (FMD) in dogs with caudal occipital malformation syndrome (COMS) and results for 16 dogs are described. In brief, a dorsal approach to the caudal portion of the occiput and arch of the atlas was made, and a high-speed drill was used to remove a portion of the occiput in the region of the foramen magnum and the dorsal aspect of C1. The meninges that were exposed were removed or marsupialized to surrounding tissues. Foramen magnum decompression was performed in 16 dogs. No intraoperative complications occurred, and postoperative complications occurred in only 2 dogs after initial surgery and in 1 of these dogs after follow-up surgery. In both dogs, postoperative complications after the initial surgery resolved without additional treatment. One dog was nonambulatory tetraparetic after follow-up surgery and died of a suspected ruptured viscus 9 days after surgery. Four dogs developed evidence of scar formation at the surgery site and required additional surgery. Overall, 14 dogs survived, 1 died, and 1 was euthanatized. Clinical signs resolved in 7 of the 14 dogs that survived, improved in 6, and did not change in 1. Results suggest that FMD may be an effective treatment for dogs with COMS, especially if performed early in the course of the disease.
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Affiliation(s)
- Curtis W Dewey
- Department of Neurology and Neurosurgery, Long Island Veterinary Specialists, 163 S Service Rd, Plainview, NY 11803, USA
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